New classes of long-lasting insecticidal nets (LLINs) incorporating two insecticides, or an insecticide and a synergist, are recommended by the World Health Organization (WHO) to prevent malaria transmitted by mosquito vectors resistant to pyrethroid and other common insecticide classes. This study was nested in a large-scale cluster-randomized controlled trial conducted in Tanzania. A series of experimental hut trials (EHTs). The following field collected LLINs were assessed: 1/OlysetTM Plus (combining piperonyl butoxide synergist and permethrin), 2/Interceptor® G2 (chlorfenapyr and alpha-cypermethrin), 3/Royal Guard® (pyriproxyfen and alpha-cypermethrin), 4/Interceptor® (alpha-cypermethrin only), 5/a new Interceptor®, and 6/an untreated net. Thirty nets of each type were withdrawn from the community at 12, 24 and 36 months after distribution and used for the EHTs. Pre-specified outcomes were 72-hour mortality for Interceptor® G2, 24-hour mortality for OlysetTM Plus, and fertility based on egg development stage for Royal Guard®. Overall; Interceptor® G2 LLINs induced higher 72-hour mortality compared to standard LLINs of the same age up to 12 months (44% vs 21%), OR: 3.5, 95% CI: 1.9 – 6.6, p-value < 0.001 and 24-hour mortality was only significantly higher in OlysetTM Plus when new (OR: 13.6, 95%CI: 4.4 – 41.3, p-value < 0.001) compared to standard LLINs but not at 12 months (17% vs 13%; OR: 2.1, 95% CI: 1.0 – 4.3; p-value = 0.112). A small non-significant effect of pyriproxyfen on Anopheles fertility was observed for Royal Guard® up to 12 months (75% vs 98%, OR: 1.1, 95% CI: 0.0 – 24.9, p-value = 0.951). There was no evidence of a difference in the main outcomes for any of the new class of LLINs at 24 and 36 months compared to standard LLINs. Interceptor® G2 LLINs showed superior bio-efficacy compared to standard LLINs for only up to 12 months and the effect of OlysetTM Plus was observed when new for all species and 12 months for An. gambiae s.l. only. The pyriproxyfen component of Royal Guard® had a short and limited effect on fertility